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A method for the synthesis of 2,3‐dihydrofuro[3,2‐c]quinolines via TfOH or TMSOTf mediated condensation of 2‐aminoaryl cyclopropyl ketones with aldehydes has been developed. The reaction proceeds under transition metal or halogen free conditions, giving access to the target molecules in 27–90% isolated yields. Mechanistic study indicates that the reaction sequence involves imine formation, intramolecular Mannich condensation, Cloke‐Wilson rearrangement, and auto‐oxidation. [ABSTRACT FROM AUTHOR]

An efficient base‐promoted intramolecular O‐arylation approach of 2‐halobenzyl 2‐hydroxyphenyl ketones toward the synthesis of dibenzo[b,f]oxepinones has been developed. The products are obtained in good to excellent isolated yields. Further extension of the strategy to the total synthesis of dihydroartocarpol D has been described. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID‐19) has spread worldwide. To date, no specific drug for COVID‐19 has been developed. Thus, this randomized, open‐label, controlled clinical trial (ChiCTR2000029853) was performed in China. A total of 20 mild and common COVID‐19 patients were enrolled and randomly assigned to receive azvudine and symptomatic treatment (FNC group), or standard antiviral and symptomatic treatment (control group). The mean times of the first nucleic acid negative conversion (NANC) of ten patients in the FNC group and ten patients in the control group are 2.60 (SD 0.97; range 1–4) d and 5.60 (SD 3.06; range 2–13) d, respectively (p = 0.008). The mean times of the first NANC of four newly diagnosed subjects in the FNC group and ten subjects in the control group are 2.50 (SD 1.00; range 2–4) d and 9.80 (SD 4.73; range 3–19) d, respectively (starting from the initial treatment) (p = 0.01). No adverse events occur in the FNC group, while three adverse events occur in the control group (p = 0.06). The preliminary results show that FNC treatment in the mild and common COVID‐19 may shorten the NANC time versus standard antiviral treatment. Therefore, clinical trials of FNC treating COVID‐19 with larger sample size are warranted. [ABSTRACT FROM AUTHOR]

Treatment of propargylamides or propargylamidines with cesium carbonate in DMSO results in the formation of the corresponding oxazoles or imidazoles in good yields. A large variety of substrates with various functional groups are tolerated. DFT study on a model substrate reveals that the reactions proceed via a sequence involving allene formation, intramolecular cyclization, and double‐bond isomerization. A cesium carbonate promoted, transition metal and halogen‐free 5‐exo‐dig type cyclization reaction for the synthesis of oxazoles and imidazoles has been developed. [ABSTRACT FROM AUTHOR]

The first total synthesis of carbazole alkaloids lansine F and clauemarazole D is described. The spectroscopic data of the synthetic molecules were identical to those displayed by the natural products, thus confirming the accuracy of the proposed structures. [ABSTRACT FROM AUTHOR]

Treatment of cyclobutanecarboxamide with bis(trifluoroacetoxy)iodobenzene, PhI(OCOCF3)2, resulted in the formation of 1-pyrroline via Hofmann rearrangement of the former followed by in situ ring expansion reaction of the cyclobutylamine intermediate. Further elaboration of this methodology to the synthesis of 2,3-dihydro-1 H-pyrrolo[2,1- a]isoquinolinium salts has also been described. [ABSTRACT FROM AUTHOR]

The base‐mediated 5‐exo‐dig type cyclization reaction of homopropargyl pyridines for the construction of indolizines has been reported for the first time. A variety of indolizine derivatives could be obtained in moderate to excellent isolated yields by treatment of homopropargyl pryidines with cesium carbonate in DMSO at 100 °C. This strategy could also be adapted to the synthesis of pyrrolo[1,2‐a]quinolines and pyrrolo[1,2‐a]pyrimidines from the corresponding homopropargylquinolines and homopropargylpyrimidines, respectively. The mechanism involves α C−H deprotonation, 5‐exo‐dig cyclization, and isomerization of the exocyclic double bond to provide the heteroaromatic system. The transformation reported herein does not require the aid of transition metal catalysts or halogens, and is thus environmentally friendly. Treatment of homopropargyl pyridines with cesium carbonate in DMSO at 100 °C resulted in the formation of indolizines in moderate to excellent isolated yields. The approach could also be readily adapted to the syntheses of pyrrolo[1,2‐a]quinolines and pyrrolo[1,2‐a]pyrimidines. [ABSTRACT FROM AUTHOR]

A regioisomer of β-lapachone and two analogs were synthesized and evaluated for their antitumor activities. All three compounds tested were found to exhibit promising activities against PC-3, HepG2, and Raji cancer cell lines in μ M range. [ABSTRACT FROM AUTHOR]

In our continuing quest to develop a metal-organic framework (MOF)-catalyzed tandem pyrrole acylation-Nazarov cyclization reaction with α,β-unsaturated carboxylic acids for the synthesis of cyclopentenone[ b]pyrroles, which are key intermediates in the synthesis of natural product (±)-roseophilin, a series of template-induced Zn-based ( 1-3) metal-organic frameworks (MOFs) have been solvothermally synthesized and characterized. Structural conversions from non-porous MOF 1 to porous MOF 2, and back to non-porous MOF 3 arising from the different concentrations of template guest have been observed. The anion-π interactions between the template guests and ligands could affect the configuration of ligands and further tailor the frameworks of 1-3. Futhermore, MOFs 1-3 have shown to be effective heterogeneous catalysts for the tandem acylation-Nazarov cyclization reaction. In particular, the unique structural features of 2, including accessible catalytic sites and suitable channel size and shape, endow 2 with all of the desired features for the MOF-catalyzed tandem acylation-Nazarov cyclization reaction, including heterogeneous catalyst, high catalytic activity, robustness, and excellent selectivity. A plausible mechanism for the catalytic reaction has been proposed and the structure-reactivity relationship has been further clarified. Making use of 2 as a heterogeneous catalyst for the reaction could greatly increase the yield of total synthesis of (±)-roseophilin. [ABSTRACT FROM AUTHOR]

The natural product cannabinol was synthesized using an intramolecular pyranone Diels-Alder cycloaddition reaction as the key step. This strategy is well adapted to access cannabinol analogues. [ABSTRACT FROM AUTHOR]

9 H-Pyrrolo[1,2- a]indol-9-ones and isomeric indeno[2,1- b]pyrrol-8-ones could be obtained in moderate to good isolated yields, by subjecting the same substrates, 2-bromophenyl N-tosyl-2-pyrrolyl ketones, to different palladium catalysts. [ABSTRACT FROM AUTHOR]

The alkaloids containing a carbazole nucleus are an established class of natural products with wide range of biological activities. A combination of thermodynamic and enzymatic activity studies provides an insight into the recognition of Clausine E by the fat mass and obesity‐associated protein (FTO). The binding of Clausine E to FTO was driven by positive entropy and negative enthalpy changes. Results also indicated that the hydroxyl group was crucial for the binding of small molecules with FTO. The structural and thermodynamic information provides the basis for the design of more effective inhibitors for FTO demethylase activity. [ABSTRACT FROM AUTHOR]

Treatment of 2‐bromoaryl pyrrole/indol‐2‐yl ketones with cesium carbonate in DMF resulted in the formation of 9H‐pyrrolo[1,2‐a]indol‐9‐ones and 10H‐indolo[1,2‐a]indol‐10‐ones in moderate to excellent isolated yields. [ABSTRACT FROM AUTHOR]

Review: 154 refs. [ABSTRACT FROM AUTHOR]